How Does Load Selection and Sex Influence 1RM Prediction Using the Minimal Velocity Threshold During Free-Weight Back...

Area of Science:

• Sports Science
• Biomechanics
• Strength and Conditioning

Background:

• The one-repetition maximum (1RM) is a key indicator of maximal strength.
• Predicting 1RM is valuable for training prescription, but traditional testing can be time-consuming and risky.
• The load-velocity relationship offers a potential alternative for 1RM prediction.

Purpose of the Study:

• To predict 1RM in the free-weight back squat using the load-velocity relationship.
• To investigate the efficacy of different minimum velocity thresholds (MVT) for 1RM prediction.
• To determine if sex-specific MVTs are necessary for accurate 1RM prediction.

Main Methods:

• Twenty-five males and twenty-five females completed a 1RM free-weight back squat test.
• Individual load-velocity relationships were established based on the 1RM test.
• Ten regression models were developed using two-point and three-point linear equations with varying MVTs (0.25, 0.30, 0.40 m·s⁻¹).

Main Results:

• Accurate 1RM prediction was achieved in males using an MVT of 0.30 m·s⁻¹.
• Accurate 1RM prediction was achieved in females using an MVT of 0.25 m·s⁻¹.
• An MVT of 0.30 m·s⁻¹ underestimated 1RM in females, and 0.40 m·s⁻¹ underestimated 1RM in both sexes.

Conclusions:

• 1RM can be accurately predicted in free-weight back squats using the load-velocity relationship.
• Sex-specific MVTs (0.30 m·s⁻¹ for males, 0.25 m·s⁻¹ for females) improve prediction accuracy.
• Regression models should exclude loads exceeding 1 m·s⁻¹ for optimal 1RM prediction.